When are you planning on flying and do you have kids?
They currently use an older fleet of planes between the US and Australia and there is no personal in-flight entertainment. But United did announce that they would be upgrading their fleet sometime last year? I'm not sure when the new planes will start to run. I have a vague recollection it might be September.
Personally, they are not my first choice airlines to fly with; despite the cheaper pricing. The last time I used them in 2010, I flew solo without my DS. My food was burnt on both the way there and the way back.
But there are a number of others on the Dis that will provide more positive views than me.